System and method for managing piston temperature in a vehicle

Abstract

A method for managing temperature of a piston of an engine of a vehicle, the method comprises determining, by a throttle position sensor connected to a controller, a throttle position of a throttle valve of the engine, determining, by an engine speed sensor connected to the controller, an engine speed (RPM) of the engine, and determining, by the controller, an estimated piston temperature based on at least the throttle position and the engine speed.

What is claimed is: 
     
         1 . A method for managing temperature of a piston of an engine of a vehicle, the method comprising:
 determining, by a throttle position sensor connected to a controller, a throttle position of a throttle valve of the engine;   determining, by an engine speed sensor connected to the controller, an engine speed (RPM) of the engine; and   determining, by the controller, an estimated piston temperature based on at least the throttle position and the engine speed.   
     
     
         2 . The method of  claim 1 , further comprising:
 determining, by the controller, a difference between a desired piston temperature and the estimated piston temperature; and   modifying, by the controller, at least one engine operation value of the engine, the modifying being based at least in part on the difference between the desired piston temperature and the estimated piston temperature.   
     
     
         3 . The method of  claim 1 , further comprising:
 in response to the controller determining that the estimated piston temperature is above a threshold piston temperature, modifying, by the controller, at least one engine operation value of the engine.   
     
     
         4 . The method of  claim 2 , wherein the at least one engine operation value is at least one of:
 an ignition timing of the engine;   a fuel pressure;   an exhaust valve position;   a fuel injection timing;   a fuel injection quantity; and   a boost pressure from a turbocharger of the vehicle.   
     
     
         5 . The method of  claim 2 , further comprising:
 determining a temperature gradient caused by modifying the at least one engine operation value;   determining, based at least on the temperature gradient and the difference between the desired piston temperature and the estimated piston temperature, a time of modification for the at least one engine operation value; and   modifying the at least one engine operation value for the time of modification.   
     
     
         6 . The method of  claim 1 , further comprising:
 determining, by an engine coolant temperature sensor connected to the controller, an engine coolant temperature;   determining, by an air temperature sensor connected to the controller, an intake air temperature;   determining, by the controller, a revised piston temperature based on at least the estimated piston temperature, the engine coolant temperature, and the intake air temperature.   
     
     
         7 . The method of  claim 1 , further comprising:
 determining at least one of:
 an engine coolant temperature by an engine coolant temperature sensor connected to the controller, and 
 an intake air temperature by a temperature sensor connected to the controller; and 
   determining, by the controller, a revised piston temperature based on the estimated piston temperature and the at least one of:
 the engine coolant temperature, and 
 the intake air temperature. 
   
     
     
         8 . The method of  claim 1 , further comprising:
 detecting, by the controller, a change in at least one engine operation value of the engine; and   in response to detecting the change in the at least one engine operation value, determining a revised estimated piston temperature based at least on the estimated piston temperature and the change in the at least one engine operation value.   
     
     
         9 . The method of  claim 8 , wherein determining the revised estimated piston temperature is further based on a time duration of the change in the at least one engine operation value. 
     
     
         10 . The method of  claim 1 , wherein determining the estimated piston temperature based on at least the throttle position and the engine speed includes retrieving the estimated piston temperature from a temperature dataset. 
     
     
         11 . The method of  claim 1 , wherein determining the estimated piston temperature comprises:
 determining a steady state temperature (T S ) based on at least the throttle position and the engine speed;   determining a temperature gradient (dT/dt) based on a calibration equation saved to the controller; and   calculating the estimated piston temperature (T) based on the steady state temperature T S , the temperature gradient dT/dt, and a time duration (1) using a temperature determination relation of:   
       
         
           
             
               T 
               = 
               
                 
                   T 
                   S 
                 
                 + 
                 
                   
                     dT 
                     dt 
                   
                   ⁢ 
                   
                     t 
                     . 
                   
                 
               
             
           
         
       
     
     
         12 . The method of  claim 11 , wherein the estimated piston temperature is recalculated for repeating time durations t. 
     
     
         13 . The method of  claim 1 , further comprising, in response to the estimated piston temperature being above a threshold piston temperature, causing, by the controller, an amount of cooling liquid to flow from a coolant container to an air intake flow path,
 the intake air flow path being defined from air entering the vehicle and into the engine.